Simel D L, Samsa G P, Matchar D B
Center for Health Services Research in Primary Care, Durham Veterans Administration Medical Center, North Carolina 27705.
J Clin Epidemiol. 1991;44(8):763-70. doi: 10.1016/0895-4356(91)90128-v.
Confidence intervals are important summary measures that provide useful information from clinical investigations, especially when comparing data from different populations or sites. Studies of a diagnostic test should include both point estimates and confidence intervals for the tests' sensitivity and specificity. Equally important measures of a test's efficiency are likelihood ratios at each test outcome level. We present a method for calculating likelihood ratio confidence intervals for tests that have positive or negative results, tests with non-positive/non-negative results, and tests reported on an ordinal outcome scale. In addition, we demonstrate a sample size estimation procedure for diagnostic test studies based on the desired likelihood ratio confidence interval. The renewed interest in confidence intervals in the medical literature is important, and should be extended to studies analyzing diagnostic tests.
置信区间是重要的汇总指标，能从临床研究中提供有用信息，尤其是在比较来自不同人群或地点的数据时。诊断试验的研究应包括试验敏感度和特异度的点估计值和置信区间。试验效率的同样重要的指标是每个试验结果水平的似然比。我们提出了一种方法，用于计算结果为阳性或阴性的试验、结果为非阳性/非阴性的试验以及按有序结果量表报告的试验的似然比置信区间。此外，我们展示了一种基于所需似然比置信区间的诊断试验研究样本量估计程序。医学文献中对置信区间重新产生的兴趣很重要，并且应扩展到分析诊断试验的研究中。
